The present invention relates to the field of image-printing devices that use paper or a similar print media to print a hardcopy from electronic data. More particularly, the present invention relates to a dual image-printing device that includes both a color inkjet print engine and a laser print engine with a dual paper-picking device that allows the selective delivery of print media from a paper or other print media supply to the two print engines.
Modern computers allow users to generate virtually any kind of document the user may desire. For example, word processing software allows a user to generate and easily edit text for documents. Spreadsheet, graphic design, desktop publishing or imaging software packages allow a user to generate or manipulate graphs, pictures, images, graphics, etc. The features and abilities of computer software continually evolve to provide the computer user with the ability to manage or generate data, text and images.
Though society is moving ahead into the digital age, for many applications it is still necessary or desirable to print a hardcopy of the documents generated on a computer. Consequently, printers have evolved along with computers to output high quality renderings on paper or other print media of the documents a user has generated on a computer.
In addition to printers, photocopiers allow users to quickly reproduce a document of which multiple copies are needed. Fax machines allow users to almost instantly transmit hardcopy documents over unlimited distances. Multi-Function Peripherals (xe2x80x9cMFPsxe2x80x9d) are devices that combine such functions as printing, copying, faxing and scanning.
As used herein, the term xe2x80x9cimage-printing devicexe2x80x9d broadly denotes any device which outputs a hardcopy document on paper or some other print medium. For example, xe2x80x9cimage-printing devicexe2x80x9d includes, but is not limited to, printers, photocopiers, fax machines, plotters, digital copiers and MFPs. The term xe2x80x9cprinterxe2x80x9d refers broadly to any device that receives electronic data from a computer and outputs a hardcopy document corresponding to that data. Thus, xe2x80x9cprinterxe2x80x9d refers, but is not limited to, electrostatic or laser printers, inkjet printers, thermal transfer printers, dot-matrix printers, plotters, etc.
All image-printing devices are fed a supply of a print medium, typically paper, on which the hardcopy document being output is rendered. While paper is the most widely used print medium, modem image-printing devices can utilize a wide variety of print media including, but not limited to, paper, cardstock, transparencies, labels, vinyl, etc. As used hereafter, the term xe2x80x9cpaperxe2x80x9d shall be understood to refer principally to paper, but it will also be understood that wherever an image-printing device is described as using paper as the print medium, any other print medium could also be used, consistent with any constraints imposed by the particular image-printing device in question.
For most image-printing devices, regardless of the type of device, the modern trend is to adapt the image-printing device to accept and use a standard size of paper, for example, 8.5 inch by 11 inch paper or A4 paper. With all image-printing devices in an office using the same type of paper, the task of supplying the devices with paper is greatly simplified.
In most cases, the output speed and reliability of an image-printing device is heavily dependent on the ability of the device to feed itself the paper or other print medium used. For example, a printer cannot output printed pages any faster than it can pull in and position the paper to be printed on. Similarly, if the paper is mishandled, the printer will jam and stop, thereby causing further delays in the printing process. Consequently, the system for feeding paper or other print medium into an image-printing device is very important and critical to the speed and reliability of the device.
Unfortunately, a trade off must usually be made between the speed and the reliability of the paper feeding system. The faster the paper is handled, the more likely is a misfeed and a consequent paper jam. If the paper is handled more slowly, a misfeed become less likely, but the output of the printing device is correspondingly reduced.
Equally important in an image-printing device is the ability to produce color or monochromatic documents. However, again, a trade off is typically encountered. Laser or electrostatic printers provide excellent resolution in a printed document, particularly with text. However, laser printers are not well adapted to color printing. Rather, laser printers that attempt to print in color typically require four passes of the print engine over the print medium to print each of the four constituent colors: cyan, magenta, yellow and black (CMYK). Additionally, laser print engines that attempt to print in color are also relatively large, slow and expensive.
In contrast, inkjet printers are well adapted to printing documents in color. However, the inkjet printer cannot entirely match the resolution and speed of the laser printer.
Consequently, there is a need in the art for an image-printing device that combines the advantages of a laser printer for monochromatic printing with the advantages of an inkjet printer for color printing. Additionally, there is a need in the art for an underlying paper feeding system that can support such a combination printing device.
The present invention is directed to an image-printing device that combines a laser printer for monochromatic printing with an inkjet printer for color printing. In this way, the best print engine can be used during the print job depending on whether a page is best printed monochromatically or in color.
The image-printing device of the present invention also preferably includes a dual paper-picking device with first and second paper-picking mechanisms. The first paper-picking mechanism feeds print media from a supply of a print medium to a first transport path that includes the laser print engine. The second paper-picking mechanism feeds print media from a supply of a print medium to a second transport path that includes the inkjet print engine. The first and second paper-picking mechanisms each preferably include a driven roller that is selectively brought into contact with the supply of print medium. The image-printing device of the present invention may also include a tray for holding the supply of a print medium, where both paper-picking mechanisms feed print media from the supply of print medium in the tray.
The image-printing device of the present invention preferably includes firmware for controlling operation of the image-printing device. The firmware receives the data of a print job, determines for each page of the print job whether that page should be printed monochromatically or in color, sends print data for that page to the laser print engine or the inkjet print engine depending on the determination of whether that page should be printed monochromatically or in color, and controls the dual paper-picking device to feed print media to that print engine receiving the print data for that page.
The image printing device of the present invention also preferably includes an output tray in which sheets of a print job printed by both the laser print engine and the inkjet print engine are interleaved. Thus, the completed print job is automatically collated for the user.
The present invention also encompasses the methods of making and using the image-printing device described above. For example, the present invention encompasses a method of printing a print job with an image-printing device that has both a laser print engine for monochromatic printing and an inkjet print engine for color printing. The method is performed by receiving the data of a print job in the image-printing device, determining for each page of the print job whether that page should be printed monochromatically or in color, and printing that page with the laser print engine or the inkjet print engine depending on the determination of whether that page should be printed monochromatically or in color.